// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_RECORD_RDATA_H_
#define NET_DNS_RECORD_RDATA_H_

#include <stdint.h>

#include <memory>
#include <string>
#include <vector>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/strings/string_piece.h"
#include "net/base/ip_address.h"
#include "net/base/net_export.h"
#include "net/dns/dns_protocol.h"

namespace net {

class DnsRecordParser;

// Parsed represenation of the extra data in a record. Does not include standard
// DNS record data such as TTL, Name, Type and Class.
class NET_EXPORT_PRIVATE RecordRdata {
public:
    virtual ~RecordRdata() { }

    virtual bool IsEqual(const RecordRdata* other) const = 0;
    virtual uint16_t Type() const = 0;

protected:
    RecordRdata();

    DISALLOW_COPY_AND_ASSIGN(RecordRdata);
};

// SRV record format (http://www.ietf.org/rfc/rfc2782.txt):
// 2 bytes network-order unsigned priority
// 2 bytes network-order unsigned weight
// 2 bytes network-order unsigned port
// target: domain name (on-the-wire representation)
class NET_EXPORT_PRIVATE SrvRecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeSRV;

    ~SrvRecordRdata() override;
    static std::unique_ptr<SrvRecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);

    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    uint16_t priority() const { return priority_; }
    uint16_t weight() const { return weight_; }
    uint16_t port() const { return port_; }

    const std::string& target() const { return target_; }

private:
    SrvRecordRdata();

    uint16_t priority_;
    uint16_t weight_;
    uint16_t port_;

    std::string target_;

    DISALLOW_COPY_AND_ASSIGN(SrvRecordRdata);
};

// A Record format (http://www.ietf.org/rfc/rfc1035.txt):
// 4 bytes for IP address.
class NET_EXPORT_PRIVATE ARecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeA;

    ~ARecordRdata() override;
    static std::unique_ptr<ARecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    const IPAddress& address() const { return address_; }

private:
    ARecordRdata();

    IPAddress address_;

    DISALLOW_COPY_AND_ASSIGN(ARecordRdata);
};

// AAAA Record format (http://www.ietf.org/rfc/rfc1035.txt):
// 16 bytes for IP address.
class NET_EXPORT_PRIVATE AAAARecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeAAAA;

    ~AAAARecordRdata() override;
    static std::unique_ptr<AAAARecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    const IPAddress& address() const { return address_; }

private:
    AAAARecordRdata();

    IPAddress address_;

    DISALLOW_COPY_AND_ASSIGN(AAAARecordRdata);
};

// CNAME record format (http://www.ietf.org/rfc/rfc1035.txt):
// cname: On the wire representation of domain name.
class NET_EXPORT_PRIVATE CnameRecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeCNAME;

    ~CnameRecordRdata() override;
    static std::unique_ptr<CnameRecordRdata> Create(
        const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    std::string cname() const { return cname_; }

private:
    CnameRecordRdata();

    std::string cname_;

    DISALLOW_COPY_AND_ASSIGN(CnameRecordRdata);
};

// PTR record format (http://www.ietf.org/rfc/rfc1035.txt):
// domain: On the wire representation of domain name.
class NET_EXPORT_PRIVATE PtrRecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypePTR;

    ~PtrRecordRdata() override;
    static std::unique_ptr<PtrRecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    std::string ptrdomain() const { return ptrdomain_; }

private:
    PtrRecordRdata();

    std::string ptrdomain_;

    DISALLOW_COPY_AND_ASSIGN(PtrRecordRdata);
};

// TXT record format (http://www.ietf.org/rfc/rfc1035.txt):
// texts: One or more <character-string>s.
// a <character-string> is a length octet followed by as many characters.
class NET_EXPORT_PRIVATE TxtRecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeTXT;

    ~TxtRecordRdata() override;
    static std::unique_ptr<TxtRecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    const std::vector<std::string>& texts() const { return texts_; }

private:
    TxtRecordRdata();

    std::vector<std::string> texts_;

    DISALLOW_COPY_AND_ASSIGN(TxtRecordRdata);
};

// Only the subset of the NSEC record format required by mDNS is supported.
// Nsec record format is described in http://www.ietf.org/rfc/rfc3845.txt and
// the limited version required for mDNS described in
// http://www.rfc-editor.org/rfc/rfc6762.txt Section 6.1.
class NET_EXPORT_PRIVATE NsecRecordRdata : public RecordRdata {
public:
    static const uint16_t kType = dns_protocol::kTypeNSEC;

    ~NsecRecordRdata() override;
    static std::unique_ptr<NsecRecordRdata> Create(const base::StringPiece& data,
        const DnsRecordParser& parser);
    bool IsEqual(const RecordRdata* other) const override;
    uint16_t Type() const override;

    // Length of the bitmap in bits.
    unsigned bitmap_length() const { return bitmap_.size() * 8; }

    // Returns bit i-th bit in the bitmap, where bits withing a byte are organized
    // most to least significant. If it is set, a record with rrtype i exists for
    // the domain name of this nsec record.
    bool GetBit(unsigned i) const;

private:
    NsecRecordRdata();

    std::vector<uint8_t> bitmap_;

    DISALLOW_COPY_AND_ASSIGN(NsecRecordRdata);
};

} // namespace net

#endif // NET_DNS_RECORD_RDATA_H_
